Transition Mechanism of Promotion/Inhibition of Ice Accretion on Overhead Ground Wires Under Electric Field Effects

Ice accretion on overhead ground wires is a significant hazard threatening the safe operation of power systems. The electric field exerts a complex bidirectional effect—both promoting and inhibiting—on ice growth, and the underlying mechanism of this transition remains unclear. This paper systematically investigates the ice accretion characteristics of overhead ground wires under different electric field intensities (0–15 kV/cm) and polarities (positive/negative DC, AC) by developing a numerical model that couples electric field and flow field interactions with supercooled droplet impact, which is then combined with energized ice accretion experiments in an artificial climate chamber. The findings reveal a “bidirectional effect” of the electric field on wire icing: at low electric field intensities (5–10 kV/cm), the electric force attracts droplets carrying opposite charges, increasing the droplet collision coefficient and promoting ice accretion, with ice length increasing compared to conditions without an electric field. At high electric field intensities (≥15 kV/cm), the “ionic wind” effect generated by corona discharge dominates, hindering droplet collision and suppressing ice accretion. Based on experimental and simulation results, a quantitative relationship between electric field intensity and collision coefficient is established, and the transition mechanism between promotion and inhibition under different electric fields is proposed. The findings of this paper provide a theoretical basis for the anti-icing design of overhead ground wires, voltage polarity selection, and the refinement of ice accretion prediction models.